A side-impact protective system with the above-mentioned general characteristics is described in U.S. Pat. No. 6,170,860 B1. In the case of the gas bag described therein, there are several pressure equalization regions in the form of pressure equalization chambers in addition to the main chambers, which can be directly inflated by the gas stream, which is released during the actuation, and which pressure equalization chambers are separated from the directly inflatable chambers by linear seals, and which, therefore, are initially not inflated when the side-impact protective system is triggered. These additional chambers have the function of ventilating the chamber after they had been inflated immediately upon actuation when an impact by the occupants of the vehicle occurred, by causing the seals to be opened as a result of the higher interior pressure produced by the impact, so that the inflation gas can pass from the immediately inflated chambers into the pressure equalization chambers. By this means, on the one hand, the desired flexibility of the initially inflated chambers, which are stressed by the impact of the occupants, is achieved, and, on the other hand, the gas which has been displaced from the initially inflated chambers remains inside the air bag, and thus provides a longer period of time during which the air bag can absorb impact energy, especially in the case of multiple impacts or in the case of an accident where the vehicle is overturned.
In the embodiment known from U.S. Pat. No. 6,170,860 B1, the pressure equalization chambers have a circumferential gas-tight seal around them, while throttled transition points have been placed in the seals for the gas that needs to be displaced from the initially inflated chambers as the interior pressure rises. While these throttled transition points permit the transfer of gas from the initially inflated chambers to the pressure equalization chambers, there is, however, still the disadvantage that a control of the gas transfer as a function of the interior pressure, which is built up during the impact of the occupants, is not possible in the initially inflated chambers.